Transfer counter



Dec. 18, 1962 A. w. HAYDON 3,069,083

TRANSFER COUNTER Filed Jan. 28. 1959 3 Sheets-Sheet 1 FIG. I

INVENTOR. ARTHUR W. HAYDON AZTTORN YS Dec. 18, 1962 A. w. HAYDON3,069,083

TRANSFER COUNTER Filed Jan. 28, 1959 3 Sheets-Sheet 2 Fl G. 4 FIG. 5

INVENTOR ARTHUR W. HAYDON ATTORNEY1mllllillflllllllllllllllllllllilltllllil Ill - Dec. 18, 1962 A. w.HAYDON 3,069,083

TRANSFER COUNTER Filed Jan. 28, 1959 23 22 FIG. 8 22 3 Sheets-Sheet 3 IINVENTOR ARTHUR w. HAYDON BY flmiwa WW ATTORNEYS- United States Patent3,069,683 TRANSFER COUNTER Arthur W. Haydon, Milford, Conn, assignor toHaydon Switch Incorporated, a corporation of Connecticut Filed Jan. 28,1959, Ser. No. 789,578 9 Claims. (Cl. 235-436) The present inventionrelates to counting devices, and more particularly to improvements intransfer counters, such as decade transfer counters, to the end thatsuch counters may be economically manufactured, are of rugged, compactdesign, and are capable of extremely high speed operation.

In conventional transfer counters, means are provided for effecting theintermittent transfer of motion from counter drums of lower orders tocounter drums of higher orders. Thus, in a decade counter, each drum iscalibrated in units of ten, and a complete revolution of a lower orderdrum effects of a revolution of the drum of the next higher order. Tofacilitate reading of the device, the transfer movement of a higherorder drum is effected during the last portion only of a rotationalcycle of the next lower drum, as when the lower order drum moves fromthe nine to the zero index position.

In counting devices of conventional design, a serious limitation isplaced upon the speed of operation due to high impact forces, whichresult from the intermittent transfer movement of the higher orderdrums. This is particularly true during the transfer movement of drumsin the upper register of a device, since all drums of a lower order movesimultaneously between the nine and Zero index positions, along with theupper register drum.

Attempts have been made, heretofore, to reduce or eliminate the heavyimpact forces of high speed counter operation. However, in allinstances, of which the pres" ent inventor is aware, the resultingmechanisms have been of a complicated nature, costly to manufacture, oflarge physical size, and susceptible to damage under prolonged, severeuse.

A principal feature of the invention resides in the provision of a noveland improved transfer counter of compact and rugged design, and of ahighly practical and advantageous construction, in which compact,reliable mechanical cam means are provided in the transfer train betweendrums, whereby forces necessary to effect transfer or indexing movementof a higher order drum are built up gradually during the rotation of thedrum of the next lower order from zero to nine. The built-up forces arethen released, when the lower order drum rotates from nine to zero,without imposing heavy impact forces upon the drive shaft. One of thespecific advantageous features of the new design is the provision ofcounter drums of molded plastic construction incorporating, as integralparts thereof, a gear driven by a train including the drum of the nextlower order, or by an input gear, a drive pinion for driving a higherorder drum, and a cam forming part of the mechanical system for storingindexing forces. The improved drums include eripheral flanges, on whichthe index numbers are provided, and the operating mechanism foreffecting transfer nrovement of higher order drums is housedsubstantially within the outline formed by the drum flanges, whereby thecomplete counter mechanism is not greatly longer than the series ofdrums.

lntaccordance with another specific feature of the invention, a deluxeform of the improved transfer counter is provided, which includesselectively operable control means providing for either intermittent orcontinuous, proportional transfer movement between counter drums. Forhigh speed operation, the control means is set to provide continuous,proportional driving of the drums, with substantially constant forcesbeing applied to all parts of the mechanism. At the end of a high speedcounting period, the control means are advantageously returned to aposition providing intermittent transfer movement, which automaticallyshifts the higher order drums to the next lower index position tofacilitate reading of the registered count. Alternatively, for operationat low speed, the new counter may be arranged to provide forintermittent transfer movement throughout the counting period, to permitreading of the counter during operation. And, to this end, the deluxeform of the new counter includes the improved arrangements of thestandard form of the counter providing for the desired, intermittenttransfer movement of the counter drums without imposing on the drivemechanism the heavy intermittent torque loads characteristic ofconventional devices.

Another advantageous feature of the invention, incorporated in thedeluxe form of the counter, resides in the provision of improved meansfor effecting rapid reset of the respective counting drums to theirinitial or zero" positions. To this end, the device of the inventionincludes means, acting individually on each drum and tending to returneach drum independently to its zero position. In combination with theforegoing, control means are provided for selectively disengaging therespective drums, one from the other, enabling each drum to return toits zero position independently and within a single revolution. Theresetting forces advantageously are applied to the drums by means ofsprings, which may be rendered ineffective by the control means duringhigh speed operation of the counter.

As one of the more specific aspects of the invention, the advantageousdeluxe features described in the foregoing paragraphs are interrelatedand combined in a single mechanism, operable by a single control member,providing a practical transfer counter device having a minimum number ofoperating parts, yet incorporating the several advantageous featuresheretofore mentioned.

Other specific features of the invention reside in specific structuraland mechanical arrangements described and illustrated in greater detailin the following specification and in the accompanying drawings, inWhich:

FIG. 1 is a longitudinal, cross-sectional view, with parts broken away,of a deluxe counter incorporating the various features of the invention;

FIGS. 2 and 3 are cross-sectional views taken along lines 22 and 3-3,respectively, of FIG. 1;

FIGS. 46 are cross-sectional views similar to FIG. 3, illustrating asequence of positions of certain operating parts of the new device;

FIG. 7 is an expanded, perspective view of the mechanism illustrated inFIGS. 3-6;

FIG. 8 is an enlarged, fragmentary, cross-sectional view, similar toFIG. 1, illustrating the operation of the transfer mechanism; and

FIG. 9 is a cross-sectional view taken generally along line 99 of FIG.1.

Referring now to the drawings, the reference numeral 10 designates ahousing open at one or both ends for receiving a frame consisting ofspaced deck plates 11, 12 connected by longitudinally disposed rods orposts 13. In the illustrated device, a shaft 14 is journalled in theframe, by bearings 15, 16 and has a portion 17 extending outward of oneend of the housing for connection to appropriate drive means (notshown). Alternatively, the shaft 14 may be stationary, and the portion17, hereafter referred to as a shaft, may constitute a separate shaftadapted to be rotated by external drive means. Mounted on the shaft 14are counter drums 18-21, advantageously provided about their peripherieswith the usual index numbers, 0-9, and arranged in registry With windows22 covered by a transparent plate 23.

aoeacss As is conventional in all transfer counters, the drum Of thelowest order-here drum 18 is driven by the sha 17, while each of thehigher order drums is driven by the drum of the next lower order. Tothis end, a pmion 24 is mounted on the shaft 17, adjacent the lowestorder drum 18, and is arranged to drive an idler gear 25. The gear 25 ismounted, advantageously by anti-friction hearings, on a bushing 26movable axially on a pin 27 anchored in the deck plate 12. The drum 18is advantageously of molded, plastic construction and has formedintegrally thereon a gear 28, which is substantially identical to thegear 24. The idler gear 25 is of such axial length as to be able, in oneaxial position, to engage the gears 24, 28 simultaneously, wherebyrotations of the shaft 14 are imparted to the lowest drum is. As will bedescribed in greater detail, the idler gear 25 may be shifted axially atdesired times, along the pin 27, and thereby taken out of engagementwith the gear 28, while retaining its engagement with the gear 24.Alternatively, releasable driving engagement between the shaft 17 anddrum 18 may be provided by means of a suitable clutch mechanism, forexample.

As illustrated best in FIG. 1, for example, the drums 1821, of moldedconstruction, comprise disc-like web sections, with axially extendingflanges forming the outer peripheries of the drums. The flange and websections form, in effect, recesses in the drums, in which a substantialportion of the operating mechanism of the counter is received, in theinterests of compactness.

Advantageously, each of the drums 1821 is mounted for free rotation withrespect to the drive shaft 14, by means such as anti-friction bearings29, means being provided to interconnect lower order drums each with adrum of the next higher order, whereby rotational movement of the lowerorder drums is transferred in a desired manner to the higher orderdrums. In accordance with the invention, each drum has fixed thereto apinion 30, which is advantageously an integral part of the drum molding.In the illustration of FIG. 1, details of the transfer gear means areshown for the drums 18, 19, it being understood that similar transfermeans is provided connecting each lower order drum with a higher orderdrum. Thus, a compound gear 31, consisting of a large diameter gear 32and a small diameter gear 33, meshes with the pinion 31 of the drum 18and with the gear 28 of the drum 19, the relation between the respectivesets of gears being such as to provide a 10:1 reduction ratio betweenthe drums 18, 19, as is typical in decade transfer counters.

The compound gear 31 is advantageously supported for anti-frictionalrotation by a bearing 34- and bushing 35, the latter being mountedslidably on a pin 36. The pin 36 is, in turn, anchored at one end in aradius arm 37 mounted rotatably on the shaft 14 by a bushing 38. Theradius arm 37 permits movement of the gear 31 about the axis of theshaft 14 while retaining the gear in proper position to mesh with thepinion and gear 28. Similar transfer gear mechanisms are provided tointerconnect the other lower order drums with drums of the next higherorder, and these mechanisms will not be described separately. However,where reference is made to corresponding elements of other mechanisms,appropriate prime reference numerals will be employed to indicatesimilarity of parts.

In conjunction with the transfer gear means connecting the respectivecounter drums, it is necessary to provide motion modifying meansoperative to limit the effectiveness of the transfer gear means toselected portions of the rotational cycle of the lower order drums.Thus, it is undesirable to provide a straight reduction gear drivebetween drums since, during fractional revolutions of lower order drums,the higher order drums will rotate fractionally from one index positiontoward the next index position. At intermediate positions, therefore, itwould be dilficult to read the drums. Accordingly, it is conventional,in the broad sense, to provide motion modifying means whereby the actionof the transfer mechanism is without effect as the lower order drummoves from its zero position to its nine position, and whereby theentire transfer movement of the higher order drum takes place during themovement of the lower order drum from its nine position to its zeroposition.

In the apparatus of the invention, the action of the transfer gear meansis modified by cams 39, advantageously formed integrally with each drum,which act upon motion compensating arms 40 to shift the transfer gear 31circurn ferentially about the shaft 14 in predetermined relation torotations of the drum 18. As shown best in FIGS. 3-6, the compensatingarm 49 is pivoted on a rod 41, which may be referred to as a controlrod, and has a cam follower 42 intermediate its ends arranged to restupon the surface of the cam 39. Adjacent each compensating arm 44? is acontrol arm 43, which is fixed to the control rod 4-1. The outer end-ofthe control arm has an enlarged opening 44 wherein, in which is receiveda pin 45 extending laterally from the compensating arm. The control arm43 also serves to anchor a spring 46, the free end 47 of which rests onthe pin 45, urging the compensating arm 40 to ivot counterclockwise, asviewed in FIGS. 3-6.

An open slot 48 is provided at the end of the arm 40 to receive arecessed end portion of the bushing 35 which mounts the transfer gear31. The slot 48 provides for relative movement of the bushing 35 towardand away from the axis of the control rod 41, but prevents relativeaxial movement of the bushing with respect to the compensating arm.

The drum 13 is illustrated in its Zero position in FIG. 3, and it willbe observed therein that the relationship etween the cam 3, and camfollower 42 is such that the follower rests in the low area of the cam,being urged to such position by the action of the spring 46 on the pin45. If the drum 18 is rotated, as by counterclockwise rotation of thedrive shaft 17, the drum 13 rotates counterclockwise, effectingclockwise rotation of the transfer gear 31 and thereby tending to effectcounterclockwise rotation of the drum 19. However, as the drum 18rotates throughout the initial of a full revolution (324) the camfollower 42 is forced away from the axis of the drive shaft 14 by thecam 39. This causes clockwise pivotal movement of the compensating arm40, to the ultimate position shown in FIG. 4. In this respect, the ca 39is of single lobe form and is contoured such that the clockwisedisplacement of the transfer gear 31 substantially exactly compensatesfor its tendency to effect counterclockwise rotation of the drum 19, sothat, in fact, no rotation of the drum 19 takes place. The transfer gear31 remains meshed with the pinion 3t and gear 23 of the drum 19, byreason of the radius arm 37, which maintains a fixed distance betweenthe axes of the drive shaft and gear shaft 36.

During the last portion of a revolution of the drum 1?, the lobe of thecam 39 passes under the cam follower 42, in the manner shown in FIG. 5,causing the compensating arm 41 to be pivoted counterclockwise under theinfluence of the spring 46. This occurs as the drum 18 rotates from itsnine to its zero index position, and the bodily movement, in acounterclockwise direction, of the transfer gear 31 during this periodeffects the desired counterclockwise transfer movement of the next drum19 through V10 revolution, or one index position.

As will be understood, the transfer of motion to the ripper registers ofdrums occurs exactly as heretofore described for all sets of drums,regardless of the number thereof.

During a counting period, it may be desirable to render ineffective thecompensating means, to avoid intermittent, accelerated movement of partsof the mechanism. Accordingly, the illustrated device includes means forrotating the control rod 41 in a. clockwise direction, to an extent suchthat the pin 45 extending laterally from each compensating arm isengaged by the lower edge of the opening 44 of each control arm, causingthe compensating arms to be pivoted clockwise to a position, shown inFIG. 6, wherein the cam follower 42 lies wholly outside the path of thecam 39. The respective transfer gears are thus effectively locked inposition, and a direct gear drive is established between the sets ofdrums. This enables the counting device to be driven at extremely highspeeds, since rotation of all the drums is uniformly related to therotation of the drive shaft 14, except for the fact that the drumsrotate progressively slower in the upper registers.

In order to read the count, following a high speed counting period, thecontrol shaft 41 is rotated counterclockwise to its initial position,permitting counterclockwise movement of the compensating arms 40 to theextent permitted by the respective earns 39. The drums then shift to theproper index positions, so that the final reading is the same as if thecontrol rod 41 had been retained in its initial position throughout thecounting period.

In accordance with one of the specific features of the invention,resetting of the respective drums to zero or starting positions may beeffected rapidly and in a substantially automatic manner by temporarilydisengaging the input drive connection to each drum. Advantageously,this is accomplished by shifting the control rod 41 axially to theright, as viewed in FIG. 1, moving the respective compensating andcontrol arms to the right to withdraw the pinio-ns 33 of the transfergears 31 axially out of engagement with the gears 28 of the respectivedrums. At the same time, the idler gear 25 (or clutch, as the case maybe), driving the first drum 18, is withdrawn axially by an arm 49, whichis rotatable but axially immovable on the control rod 41 and engages thebushing 26 mounting the idler gear 25.

It will be observed in FIG. 1 that the axial length of the cams 3? andthe pinions 36 is such as to accommodate the required axial movement ofthe cam followers 42 and transfer gears 31, while retaining the gears30-32 in mesh and maintaining contact between the cams and camfollowers. Accordingly, when the control rod 41 is shifted axially, to alimit position determined by a shoulder 50 at the left end of the rod,each of the drums 18-21 is freely rotatable on the drive shaft 14, eachindependently of the others. When the drums are thus released, theaction of the spring urged cam followers 42 on the cams 39 rotates thecams and drums, until the cam follower reaches the lowest point on thecam, illustrated in FIG. 3, at which time the drum is in its starting orzero position. The maximum rotation of any drum, during resetting, is Wof a revolution. It should be noted that the follower 42c, cooperatingwith the highest order drum, functions only to return the drum to itszero position and does not act as a motion modifier, as do the otherfollowers.

When all the drums are aligned in their zero positions, the control rod41 may be released and allowed to shift to the left, under the action ofa spring 51, reestablishing the driving engagement of the idler gear andthe transfer gears 31. In this respect, the transfer gears areadvantageously retained in mesh with at least .pne gear of the train atall times, so that the teeth of these gears are properly aligned forre-engagement, when the drums are returned to zero positions.

Any suitable arrangement may be employed for actuating the control rod41, including automatic, remotely actuated mechanisms. For purposes ofillustration only, a manual actuating means is shown, comprising amanipulating wheel 52 mounted rotatably and slidably on a rod 53anchored at one end in the end Wall 54 of the housing. A pinion 55 isfixed to the wheel 52 and meshes with a gear segment 56 fixed on thecontrol shaft 41.

Suitable stop means and/or detent means (not shown) may be provided tolock the wheel releasably in a preset position. With reference to FIG.9, the device is set for slow speed operation or for reading by movingthe wheel 52 to one limit position, in which the rotary position of thecontrol rod 41 and control arms 43 is as indicated in FIGS. 3-5. Tocondition the device for high speed operation, the control wheel 52 isrotated counterclockwise, as viewed in FIG. 9, to a second limitposition. Such rotation of the control wheel causes the control rod 41to be rotated clockwise, to the position shown in FIG. 6, wherein thecam followers 42 are raised out of the paths of the cams 39.

At the end of a high speed counting operation, the control wheel 52 isfirst rotated to its first limit position, returning the cam followersto the cams to allow reading of the device. The control wheel 52 is thenshifted axially thereby engaging the end of the control rod 41 andcausing it to shift axially to the right as illustrated in FIG. 1. Thegears 25 and 31 are thereby shifted axially, to reset positions, asshown in FIG. 8.

One of the advantageous features of the deluxe form of the deviceresides in the provision of means providing a direct gear drive for highspeed operation, which is selectively operable to adjust the respectivepositions of the drums at the end of a counting period to indexpositions, in which the drums may be easily read. Another valuablefeature resides in the novel arrangement for returning the respectivedrums to Zero or starting positions at the end of counting operations.Each drum is acted upon by a spring urged cam follower, which tends toroll down-hill on a cam to return the drum to zero position, wheneverthe drum is permitted to rotate freely. Thus, by providing a simplifiedcontrol mechanism, capable of disengaging each drum from the drivesystem and permitting free and independent rotation thereof, all of thedrums may be quickly reset to zero, with no rewinding or otherapplication of external motion. A further significant feature of theillustrated device resides in the advantageous combination of thefeatures above mentioned, whereby the cam and cam follower meansemployed during slow speed counting, and during reading, for modifyingor compensating the transfer means, is utilized following a countingperiod for resetting the counting drums to zero. The overall arrangementprovides a highly versatile and substantially improved counter device ofrelatively simplified design.

Although only the deluxe form of the device has been illustrated, itwill be understood certain basic features of the invention are retainedin the standard form of the device, in which the shifting and resettingmeans may be omitted. The standard form of device retains the manyadvantages resulting from the use of compact, onepiece molded drumsincluding a gear, a pinion and a cam, and also incorporates the improvedstructural arrangement of the motion modifying means, including aplanetary gear movable about the axis of the drum shaft and acam-actuated arm for moving the planetary gear through its limitedorbital path.

It should be understood, therefore, that the form of the inventionherein specifically illustrated and described is intended to berepresentative only, as certain changes may be made therein withoutdeparting from the clear teachings of the disclosure. Accordingly,reference should be made to the following appended claims in determiningthe full scope of the invention.

I claim:

1. A transfer counter comprising a plurality of register drums,lightweight resiliently biased floating transfer means interconnectinglower order drums with higher order drums and operative normally toeffect rotation of a higher order drum in predetermined relation torotations of the drum of the next lower order, cam means operated bylower order drums for shifting the floating transfer means duringportions of the rotational cycles of the lower order drums wherebyrotation of a higher order 7 drum is caused only during selectedportions of rotational cycles of a drum of the next lower order, saidtransfer means comprising reduction gears interconnecting adjacentdrums, lightweight resiliently biased movable means mounting thereduction gears, said cam means acting on the movable means to shift theposition of a set of reduction gears in accordance with rotations of alower order drum and in a direction and at a speed to offset relativemovement between the reduction gears and the higher order drum driventhereby, during a portion of the rotational cycle of the drum of thenext lower order, and in an opposite direction during the remainingportion of the rotational cycle to return the gears to an initialposition, and a control means comprising means selectively to positivelydisengage said cam means from said movable means to permit high speedoperation of the counter and to engage said cam means to facilitatereading of the counter.

2. The transfer counter of claim 1, in which the cam means includes camscarried by lower order drums, said movable means including cam followersadapted to engage the respective cams, and control means for renderingthe cam means ineffective to shift the floating transfer means, saidcontrol means including means operative selectively to hold the camfollowers out of contact with the cams and to urge the followersresiliently against the cams.

3. The transfer counter of claim 2, in which the drums are mounted forrotation about a common axis, a control rod mounted parallel to saidaxis and extending along said drums, motion compensating arms extendingbetween sets of drums and each engaging a cam follower and a set ofreduction gears, spring means normally urging said arms in a directionto press the followers against the cams, said control rod operativelyengaging the arms to move said arms to a position preventing contactbetween the followers and earns.

4. The transfer counter of claim 3, in which the compensating arms arepivoted on said control rod, the control rod being mounted for limitedrotation and carrying control arms engageable with the compensating armsto raise the compensating arms out of contact with the cams.

5. The transfer counter of claim 2, in which the control means isoperable selectively to disengage the transfer means to permitindependent rotation of the drums, whereby the drums are returned tozero positions by the action of the cam followers on the cams.

6. The transfer counter of claim 5, in which the control means comprisesa rod mounted for axial and rotational movement, said rod being movablerotationally to move the cam followers into and out of contact with thecams and movable axially to effect disengagement of the transfer means.

7. The transfer counter of claim 5, in which the transfer meanscomprises gears on adjacent lower and higher order drums, and gear meansinterconnecting said gears, said control means comprising means foreffecting relative axial movement between said gears and gear means,whereby the gear means is disengaged from one of the gears.

8. A transfer counter comprising a drum shaft, a plurality of drumsmounted on said shaft for rotation about its axis, means for rotating alower order drum, a transfer pinion carried by said lower order drum, adifferential planetary transfer gear meshing with said transfer pinion,a radius arm mounted for pivotal movement on said drum shaft andpositioned between said lower order drum and the drum of the next higherorder, said planetary transfer gear being mounted on said radius arm forrotation about an axis laterally offset from the axis of said drum shaftand for limited orbital movement about the axes of said shaft, saidradius arm and said planetary transfer gear being positionedsubstantially within the peripheral outline of said drums and saidlaterally offset axis lying within the peripheral outline of said drums,a transfer gear carried by the drum of the next higher order and meshingwith said planetary transfer gear, a compensating cam carried by saidlower order drum within the peripheral outline of said drums, acompensating arm mounted for pivotal movement about a predeterminedfixed axis and extending between said lower and higher order drums, saidcompensating arm being connected to said radius arm and said planetarytransfer gear, said predetermined fixed axis lying generally on theopposite side of said drum shaft from the point of connection betweensaid compensating arm and said radius arm, cam follower means on saidcompensating arm positioned between said predetermined fixed axis andsaid planetary transfer gear and engaging the surface of saidcompensating cam, and resilient means urging said cam follower meansinto engagement with said compensating cam, said compensating cam beingcontoured to move said compensating arm, and hence said radius arm andplanetary transfer gear in a manner to retain said higher order drumsubstantially motionless during a predetermined portion of a revolutionof said lower order drum and to effect transfer movement of said higherorder drum through a predetermined indexing increment during theremaining portion of a revolution of said lower order drum.

9. A transfer counter comprising a drum shaft, a plurality of drumsmounted on said shaft for rotation about its axis, means for rotating alower order drum, a transfer pinion carried by said lower order drum, adifferential planetary transfer gear meshing with said transfer pinion,a radius arm mounted for pivotal movement on said drum shaft andpositioned between said lower order drum and the drum of the next higherorder, said planetary transfer gear being mounted on said radius arm forrotation about an axis laterally offset from the axis of said drum shaftand for limited orbital movement about the axis of said shaft, atransfer gear carried by the drum of the next higher order and meshingwith said planetary transfer gear, a compensating cam carried by saidlower order drum, a compensating arm mounted for pivotal movement abouta predetermined fixed axis and extending between said lower and hi herorder drums, said compensating arm having an offset portion passingaround said shaft and having a free end located generally on theopposite side of said shaft from said predetermined fixed axis, saidradius arm having a portion extending generally directly away from saidpredetermined fixed axis, said portion being connected to the free endof said compensating arm, and cam follower means on the offset portionof said compensating arm engaging the surface of said compensating cam,said compensating cam being contoured to move said compensating arm, andhence said radius arm and planetary transfer gear in a manner to retainsaid higher order drum substantially motionless during a predeterminedportion of a revolution of said lower order drum and to effect transfermovement of said higher order drum through a predetermined indexingincrement during the remaining portion of a revolution of said lowerorder drum.

References tilted in the file of this patent UNITED STATES PATENTS1,148,516 irion Aug. 3, 1915 1,913,983 Gardner June 13, 1933 2,344,627Mixer a Mar. 21, 1944 2,405,626 Williams Aug. 13, 1946 2,456,101Yeasting Dec. 14, 1.948 2,613,033 Pfleger Oct. 7, 1952 2,622,805 AveryDec. 23, 1952 2,680,562 Dalzell June 8, 1954 2,920,816 Greenhow Jan. 12,1960

